DB-MFENet: A Dual-Branch Multi-Frequency Feature Enhancement Network for Hyperspectral Image Classification

HSI classification is essential for monitoring and analyzing the Earth’s surface, with methods utilizing convolutional neural networks (CNNs) and transformers rapidly gaining prominence and advancing in recent years. However, CNNs are limited by their restricted receptive fields and can only process local information. Although transformers excel at establishing long-range dependencies, they underutilize the spatial information of HSIs. To tackle these challenges, we present the multi-frequency feature enhancement network (DB-MFENet) for HSI classification. First, orthogonal position encoding (OPE) is employed to map image coordinates into a high-dimensional space, which is then combined with corresponding spectral values to compute a multi-frequency feature. Next, the multi-frequency feature is divided into low-frequency and high-frequency components, which are separately enhanced through a dual-branch structure and then fused. Finally, a transformer encoder and a linear layer are employed to encode and classify the enhanced multi-frequency feature. The experimental results demonstrate that our method is efficient and robust for HSIs classification, achieving overall accuracies of 97.05%, 91.92%, 98.72%, and 96.31% on Indian Pines, Salinas, Pavia University, and WHU-Hi-HanChuan datasets, respectively.